This revised application is for renewal of R01 HD23264 with a new title that reflects the evolving focus of our research program. Our goal is to understand bio-psychosocial processes associated with pediatric chronic pain with the aim of informing prevention and treatment. Youth with chronic abdominal pain (CAP) have served as a prototype in our study of pain not associated with significant medically explained pathology. These youth are thought to be at risk for functional gastrointestinal disorders (FGIDs), headache, other chronic pain disorders, and psychiatric disorders as adolescents and adults. However, no prospective studies have systematically assessed these outcomes. Additional information is needed to characterize physical, emotional, and functional outcomes of CAP, discover risk factors for adverse outcomes, and identify psychological, behavioral, and physiological factors that may influence the course of CAP from childhood to adolescence and young adulthood. This application capitalizes on our existing landmark database of more than 800 patients evaluated for CAP at ages 8 through 15 years and a similar age control group of 350 well children. Our sample presents a unique opportunity to identify predictors of long-term health and psychosocial outcomes of pediatric onset CAP for individuals in our database who will be adolescents and young adults (ages 13-28 years) at follow-up. Former study participants with pediatric onset-CAP and those previously serving as well controls will be contacted for detailed psychosocial and laboratory follow-up assessment. Thus, we will evaluate CAP patients as they pass through the "age of risk" for several disorders associated with considerable impairment and health service use. We aim to (1) examine health and functional outcomes (including diagnostic criteria for FGIDs, chronic pain disorders, and psychiatric disorders) in adolescents and adults with pediatric onset CAP compared to well controls, (2) assess the relation between baseline risk factors and long-term outcomes and, (3) as a follow-up to our diary study that linked acute stress to CAP symptoms, use laboratory methods to examine experimentally the impact of acute stressors on symptom exacerbation and physiological reactivity across CAP and well controls, and identify potential moderators of the response to stressors. Relevance of this project to public health: The study will identify characteristics of youth with CAP who are most likely to develop psychiatric disorders and chronic pain as adolescents and young adults and will suggest factors that should be addressed in prevention and treatment efforts.